JP2753588B2 - Rare earth iron-based alloy sintered magnet having p-xylylene polymer film and its manufacturing method - Google Patents

Rare earth iron-based alloy sintered magnet having p-xylylene polymer film and its manufacturing method

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Publication number
JP2753588B2
JP2753588B2 JP1175645A JP17564589A JP2753588B2 JP 2753588 B2 JP2753588 B2 JP 2753588B2 JP 1175645 A JP1175645 A JP 1175645A JP 17564589 A JP17564589 A JP 17564589A JP 2753588 B2 JP2753588 B2 JP 2753588B2
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JP
Japan
Prior art keywords
xylylene
polymer film
rare earth
atomic
film
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP1175645A
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Japanese (ja)
Other versions
JPH0341703A (en
Inventor
通裕 根本
正俊 中山
弘一 矢島
国博 上田
正典 柴原
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TDK Corp
Original Assignee
TDK Corp
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Priority to JP1175645A priority Critical patent/JP2753588B2/en
Priority to US07/497,549 priority patent/US5154978A/en
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Publication of JP2753588B2 publication Critical patent/JP2753588B2/en
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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
    • H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
    • H01F41/026—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets protecting methods against environmental influences, e.g. oxygen, by surface treatment

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Environmental & Geological Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Hard Magnetic Materials (AREA)
  • Manufacturing Cores, Coils, And Magnets (AREA)
  • Polyoxymethylene Polymers And Polymers With Carbon-To-Carbon Bonds (AREA)

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は腐食し易い稀土類鉄系磁石の耐食性を改善す
る技術に関し、特に稀土類−硼素−鉄系磁石に気相ｐ−
キシリレン重合膜又は塩素化ｐ−キシリレン重合膜を形
成してなる耐食性磁石とその製造法に関する。Description: TECHNICAL FIELD The present invention relates to a technique for improving the corrosion resistance of a rare-earth iron-based magnet which is susceptible to corrosion.
The present invention relates to a corrosion-resistant magnet having a xylylene polymer film or a chlorinated p-xylylene polymer film formed thereon and a method for producing the same.

本発明によると、保護被覆と磁石との結合力が大き
い。According to the present invention, the bonding strength between the protective coating and the magnet is large.

（従来技術とその問題点） 従来高エネルギー積磁石としては、Sm−Co系磁石が用
いられてきたが、コスト、機械加工性、より高いエネル
ギー積といった点で有利な稀土類鉄系磁石が最近注目さ
れ、特に原子比で８〜30原子％の稀土類元素（Ｙを含
む）、２〜28％原子のＢ、および残部Fe（42〜90原子
％）および不可避不純物からなる組成が効果的であるこ
とが見出されている。(Prior art and its problems) Conventionally, Sm-Co based magnets have been used as high energy product magnets, but rare earth iron based magnets, which are advantageous in terms of cost, machinability and higher energy product, have recently been developed. Attention has been paid particularly to a composition consisting of a rare earth element (including Y) in an atomic ratio of 8 to 30 atomic%, B of 2 to 28 atomic%, and the balance of Fe (42 to 90 atomic%) and unavoidable impurities. It has been found that there is.

ところが、稀土類鉄系磁石はSm−Co系に比べ、耐食性
という面では劣り、種々の表面保護処理が検討されてい
る状況にある。However, rare earth iron-based magnets are inferior to Sm-Co magnets in terms of corrosion resistance, and various surface protection treatments are being studied.

稀土類鉄系磁石は焼結法および急冷法で作製されてい
る。この系の磁石は酸化し易いNd、Feを多く含むので、
耐薬品性、特に酸、アルカリに弱く、湿式めっき等の表
面処理では、酸、アルカリ等による前処理或いはめっき
工程中に表面が侵されたり、たとえめっきが出来ても、
内部に侵入した薬品の影響により、内部腐食が発生した
り、結晶粒間が侵食されることで磁気特性が低下する。Rare earth iron-based magnets are manufactured by a sintering method and a quenching method. Since this type of magnet contains a lot of Nd and Fe that are easily oxidized,
Chemical resistance, especially weak to acid and alkali, surface treatment such as wet plating, the surface is attacked during the pretreatment or plating process with acid, alkali, etc., even if plating can be done,
Due to the effect of the chemicals that have penetrated inside, internal corrosion occurs, or the erosion between crystal grains deteriorates magnetic properties.

この問題を解決する方法として各種の方法が提案され
ている。Various methods have been proposed to solve this problem.

基本的な方法は稀土類鉄系焼結磁石の表面に、耐食性
のNi、Ti、酸化又は炭化Ti、その他の金属又は化合物を
イオンプレーテイング、イオンスパッタリング等の気相
めっき法によりめっきして保護層を形成することであ
る。場合により更にクロメート処理をして耐食性を向上
するなどの方法や（特開昭61−150201号、特開昭61−16
6116号、特開昭63−9908号、特開昭63−110706号）、基
体磁石との間の結合力を増すために気相めっき層を磁石
に拡散させる方法もある（特開昭62−120002号）。とこ
ろが基体磁石は粒子間に隙間のある多孔質であるため、
気相めっき層を形成しても磁石表面には細孔が存在して
おり、酸、アルカリ、水分等が細孔に捕捉され、侵食を
生じる。この問題を避けるために気相めっきに続いて金
属球で表面を機械的に衝撃する封孔処理し（ショットピ
ーニング）、その後でクロメート処理をすることが提案
されている（特開昭63−9919、特開昭63−120003号）。
しかし、この方法でも充分な封孔処理は出来ないので、
更に合成樹脂の塗料を塗布して残った細孔を塞ぐことが
提案されている（特開昭62−120004号）。しかし、この
方法では封孔処理の乾燥工程、硬化処理等、の工程を要
し、工程がますます複雑になるだけでなく、樹脂塗料中
に含まれた水分がそのまま細孔内に捕捉されたままにな
るため腐蝕による磁石の経時的な劣化を回避することが
出来ない。又塗料を塗布する場合塗布膜厚を厚くしない
と防錆効果は出ず、その結果寸法精度が出しにくい欠点
がある。The basic method is to protect the surface of rare earth iron-based sintered magnets by plating corrosion resistant Ni, Ti, oxidized or carbonized Ti, or other metals or compounds by vapor plating such as ion plating and ion sputtering. Forming a layer. In some cases, a method of improving the corrosion resistance by further performing a chromate treatment or the like (JP-A-61-150201, JP-A-61-16
No. 6116, JP-A-63-9908 and JP-A-63-110706), and a method of diffusing a vapor-phase plating layer into a magnet in order to increase the bonding force between the base magnet and the magnet (Japanese Patent Application Laid-Open No. Sho 62-1987). No. 120002). However, since the base magnet is porous with gaps between the particles,
Even if a vapor phase plating layer is formed, pores still exist on the magnet surface, and acids, alkalis, moisture, and the like are trapped in the pores and cause erosion. In order to avoid this problem, it has been proposed to perform a sealing treatment (shot peening) in which the surface is mechanically impacted with metal spheres following the vapor phase plating, followed by a chromate treatment (JP-A-63-9919). And JP-A-63-120003).
However, this method does not provide sufficient sealing,
Furthermore, it has been proposed to coat the remaining pores by applying a coating of a synthetic resin (JP-A-62-120004). However, this method requires steps such as drying and curing of the sealing process, which not only makes the process more complicated, but also allows the water contained in the resin paint to be trapped in the pores as it is. Therefore, deterioration of the magnet over time due to corrosion cannot be avoided. In the case of applying a paint, the rust-preventing effect is not obtained unless the coating film thickness is increased, and as a result, there is a drawback that dimensional accuracy is hardly obtained.

また、この系の磁石、特にこの系の焼結磁石にプラズ
マ重合被覆を設けることは知られているが（特開昭63−
6811）、従来の多元素系被膜では充分な重合度が得難か
った。たとえばアクリル酸などではプラズマ重合中に活
性な酸素が存在し、プラズマ重合と同時にプラズマエッ
チングが起こる。このため保護重合膜の硬度、ち密性が
十分でなく又重合度も低い。そのため十分なガスバリヤ
ー性が得られないなど、耐食性保護膜として充分に機能
できない。It is also known to provide a plasma polymerization coating on a magnet of this type, particularly a sintered magnet of this type (Japanese Patent Laid-Open No.
6811), it was difficult to obtain a sufficient degree of polymerization with the conventional multi-element coating. For example, in the case of acrylic acid, active oxygen is present during plasma polymerization, and plasma etching occurs simultaneously with plasma polymerization. For this reason, the hardness and compactness of the protective polymer film are not sufficient, and the degree of polymerization is low. For this reason, it cannot function sufficiently as a corrosion-resistant protective film, for example, a sufficient gas barrier property cannot be obtained.

また、保護被覆として稀土類焼結金属磁石の表面に高
分子樹脂膜を形成することも行なわれているが（特開昭
61−198221号公報、同56−81908号公報、同60−63901号
等）、高分子樹脂膜は透湿性、酸素透過性が大きく、稀
土類焼結金属磁石との親和性が低いので、充分な接着を
確保することができない。また弗素樹脂のように高温焼
付けを要するために磁石の酸化を招くもの、エポキシ樹
脂などのように耐食性で劣るものなど各種のものがある
が、接着性と耐食性の両者を兼ね備えた膜は提供されて
いない。更にキシレン樹脂を真空蒸着で成膜することも
提案されているが、重合度は低く、耐食性に問題がある
（特開昭55−103714）。In addition, a polymer resin film is formed on the surface of a rare earth sintered metal magnet as a protective coating (see, for example,
61-198221, 56-81908, 60-63901, etc.), the polymer resin membrane has high moisture permeability and oxygen permeability, and has a low affinity for rare earth sintered metal magnets. Adhesion cannot be ensured. In addition, there are various types such as a fluororesin which requires high-temperature baking to cause oxidation of the magnet and an inferior corrosion resistance such as an epoxy resin, but a film having both adhesiveness and corrosion resistance is provided. Not. Further, it has been proposed to form a film of xylene resin by vacuum evaporation, but the degree of polymerization is low and there is a problem in corrosion resistance (Japanese Patent Laid-Open No. 55-103714).

（発明の目的） 従って本発明の目的は耐食性の良い稀土類焼結金属磁
石を提供すること、及びその製造方法を提供することに
ある。(Object of the Invention) It is therefore an object of the present invention to provide a rare earth sintered metal magnet having good corrosion resistance, and to provide a method for producing the same.

（発明の概要） 本発明は、稀土類元素（Ｙを含む）−硼素−鉄系合金
焼結体の表面に気相めっき層と、それに続く気相法ｐ−
キシリレン重合膜又は塩素化ｐ−キシリレン重合膜の保
護被覆を形成したことを特徴とする耐食性永久磁石を提
供する。(Summary of the Invention) The present invention relates to a rare earth element (including Y) -boron-iron-based alloy sintered body having a vapor phase plating layer formed on a surface thereof, followed by a vapor phase method p-phase.
Provided is a corrosion-resistant permanent magnet, wherein a protective coating of a xylylene polymer film or a chlorinated p-xylylene polymer film is formed.

本発明はまた稀土類元素−ホウ素−鉄系合金焼結体の
表面に金属上記を接触させてめっき相を形成し、次いで
ｐ−キシリレン二量体又は塩素化ｐ−キシリレン二量体
を熱分解してｐ−キシリレン又は塩素化ｐ−キシリレン
のラジカルを形成し、このラジカルを前記めっき層の表
面で重合させて保護被覆を形成することにより、上記の
耐食性永久磁石を製造する。The present invention also relates to a method for forming a plating phase by bringing a metal into contact with the surface of a rare earth element-boron-iron alloy sintered body, and then thermally decomposing p-xylylene dimer or chlorinated p-xylylene dimer. Thus, a radical of p-xylylene or chlorinated p-xylylene is formed, and the radical is polymerized on the surface of the plating layer to form a protective coating, thereby producing the above-described corrosion-resistant permanent magnet.

気相法ｐ−キシリレン重合膜又は塩素化ｐ−キシリレ
ン重合膜は耐食性に優れたものであるが、基体に対する
密着性が極めて悪いことが知られている。ところが本発
明によると、気相法ｐ−キシリレン重合膜又は塩素化ｐ
−キシリレン重合膜の保護被覆の固有の性質による極め
て高い耐食性を生かしながら接着性の悪さを補うことに
より耐食性の高い稀土類鉄系焼結合金磁石が提供でき
る。その上本発明によると保護被覆は気相重合であるた
めラジカルは細孔の中まで入り込んで重合する結果基体
焼結合金に対して結合性が大きくなり剥離しにくくな
る。このため結果的に永久磁石の耐食性及び耐久性は更
に向上する。It is known that a vapor-phase p-xylylene polymer film or a chlorinated p-xylylene polymer film has excellent corrosion resistance, but has extremely poor adhesion to a substrate. However, according to the present invention, a p-xylylene polymer film formed by a gas phase method or a chlorinated p-film is used.
-A rare earth iron-based sintered alloy magnet having high corrosion resistance can be provided by making use of the extremely high corrosion resistance due to the inherent properties of the protective coating of the xylylene polymer film and compensating for the poor adhesion. Furthermore, according to the present invention, since the protective coating is a gas phase polymerization, the radicals penetrate into the pores and polymerize, so that the bonding to the base sintered alloy is increased and the protective coating is hardly peeled off. As a result, the corrosion resistance and durability of the permanent magnet are further improved.

（発明の具体的な説明） 稀土類鉄系焼結合金 本発明で保護される稀土類鉄系焼結合金は一般に稀土
類元素８〜30原子％、硼素２〜28原子％、及び鉄42〜90
原子％を主成分とし公知の方法により焼結処理して得ら
れる。稀土類元素としては例えば特開昭62−123004号に
示されている様な、Nd、Pr、Dy、Ho、Tbの少なくとも一
種と、La、Ce、Sm、Cd、Er、Eu、Tm、Yb、Lu、Ｙのうち
の少なくとも一種からなる。この組成の磁石は磁気特性
は極めて優れているが、結晶が柱状に発達し結晶粒の間
に隙間が出来ることが知られている。本発明はこのよう
な多孔質表面を有する稀土類鉄系焼結合金をｐ−キシリ
レン重合膜又は塩素化ｐ−キシリレン重合膜で物理的に
封孔するものであるから、焼結合金の組成には直接依存
せず、合金の表面状態に依存することに注意されたい。(Specific description of the invention) Rare earth iron based sintered alloy The rare earth iron based sintered alloy protected by the present invention is generally 8 to 30 atomic% of rare earth element, 2 to 28 atomic% of boron and 42 to 42% of iron. 90
It is obtained by sintering by a known method with atomic% as a main component. Examples of rare earth elements include at least one of Nd, Pr, Dy, Ho, Tb and La, Ce, Sm, Cd, Er, Eu, Tm, Yb as shown in JP-A-62-123004. , Lu, and Y. Magnets of this composition have very good magnetic properties, but it is known that crystals develop into columnar shapes and gaps are formed between crystal grains. The present invention physically seals the rare earth iron-based sintered alloy having such a porous surface with a p-xylylene polymer film or a chlorinated p-xylylene polymer film. Note that is not directly dependent on the surface state of the alloy.

保護膜 本発明では保護膜が２層構造を成し、第１層が気相め
っき層、第２層が気相ｐ−キシリレン重合膜又は塩素化
ｐ−キシリレン重合膜よりなる。Protective Film In the present invention, the protective film has a two-layer structure, the first layer is a vapor-phase plating layer, and the second layer is a vapor-phase p-xylylene polymer film or a chlorinated p-xylylene polymer film.

気相重合ｐ−キシリレン重合膜又は塩素化ｐ−キシリ
レン重合膜は水分及び塩素に対して極めて良好なバリヤ
ー性を有し、そのため極めて優れた耐食性を有する材料
として知られているがこのものを稀土類鉄系磁石の保護
に使用することは従来試みられていない。そこで本発明
者はこれらの重合膜を直接稀土類鉄系焼結合金の表面に
形成することを試みたが接着性が極めて悪く剥離し易い
ことが分かった。A gas phase polymerized p-xylylene polymer film or a chlorinated p-xylylene polymer film has a very good barrier property against moisture and chlorine, and is therefore known as a material having extremely excellent corrosion resistance. No attempt has been made to use it for protecting ferrous magnets. Therefore, the present inventor tried to form these polymer films directly on the surface of the rare earth iron-based sintered alloy, but found that the adhesion was extremely poor and the film was easily peeled.

発明者は気相法ｐ−キシリレン重合膜及び塩素化ｐ−
キシリレン重合膜を施す前に、各種の前処理を試みた結
果、気相めっきによって予め金属化合物層又は金属層を
形成しておくことにより重合体の接着性が格段に向上す
ることを見出した。この結果は意外であった。気相めっ
き層はある程度活性な表面を有するとしても気相重合ｐ
−キシリレン重合膜及び塩素化ｐ−キシリレン重合膜と
は通常なら充分な結合力を生じないからである。これは
ｐ−キシリレンラジカルが第１層の表面に付着する際
に、基体焼結合金の細孔を大部分保存している細孔内に
侵入し、細孔内で重合して細孔を完全に充填してしま
い、そのためアンカー効果を生じていることと、めっき
層の表面がある程度活性になっているとが共同している
のであろう。この推定は磁石の断面をSEM写真で観察す
ることにより確認出来た。このことにより磁石の耐食性
が完全であることと、保護膜第２層であるｐ−キシリレ
ン又は塩素かｐ−キシリレン重合膜の密着性が良いこと
が理解出来る。保護膜第１層と第２層はお互いの欠点を
補強して完全な保護膜となっている。The inventor has proposed a vapor-phase p-xylylene polymer film and a chlorinated p-
As a result of various pretreatments before applying the xylylene polymer film, it was found that the adhesiveness of the polymer was significantly improved by forming a metal compound layer or a metal layer in advance by vapor phase plating. This result was surprising. Even if the vapor phase plating layer has a somewhat active surface,
This is because the xylylene polymer film and the chlorinated p-xylylene polymer film usually do not produce a sufficient bonding force. This is because when the p-xylylene radical adheres to the surface of the first layer, it penetrates into the pores preserving most of the pores of the base sintered alloy and polymerizes in the pores to form pores. It may be because the filling is completed and thus the anchor effect is caused, and the surface of the plating layer is activated to some extent. This estimation was confirmed by observing the cross section of the magnet with an SEM photograph. From this, it can be understood that the corrosion resistance of the magnet is perfect and that the adhesion of the p-xylylene or chlorine or p-xylylene polymer film as the second layer of the protective film is good. The protective film first layer and the second layer reinforce each other's defects to form a complete protective film.

保護膜第１層 保護膜のうち第１層は多孔質である稀土類鉄系焼結合
金の表面に直接形成される気相めっき層である。気相め
っき層は例えば特開昭61−150201号に記載されているよ
うな各種の公知の気相めっき法で形成出来る。この方法
としては、真空蒸着法、イオンスパッタリング法、イオ
ンプレーテイング法、イオン蒸着法（IVD）、プラズマ
蒸着法（CVD）等があり、真空蒸着法は、原料を抵抗加
熱、電子ビーム加熱、RF誘導加熱などの方法により加熱
蒸発させて原子状又は分子状蒸気を作り、これを焼結合
金の表面に付着させる方法である。イオンスパッタリン
グ法は真空容器内にArなどの不活性ガスを導入し、放電
を作用させてイオン化し、これを電界により加速して原
料ターゲットを衝撃し、原料のイオンを形成し、それを
焼結合金の表面に付着させる方法である。イオンプレー
テイング法は原料を抵抗加熱、電子ビーム加熱、RF誘導
加熱などの方法により加熱蒸発させて蒸気を作り、これ
に熱電子を衝突させ原料の分子又は原子のイオン流を作
り、これを電界によって加速し磁石の表面に付着製膜す
方法である。イオン蒸着法は電子銃、アーク放電等によ
って蒸発させた原料蒸発物と、原料イオン源からのイオ
ンとを同時に且つある割合で磁石表面に付着させる方法
である。プラズマ蒸着法は真空室に減量ガスを導入し、
このガスを放電等によりプラズマ化し、磁石表面に製膜
する方法である。Protective Film First Layer The first layer of the protective film is a vapor phase plating layer formed directly on the surface of a porous rare earth iron-based sintered alloy. The vapor phase plating layer can be formed by various known vapor phase plating methods as described in, for example, JP-A-61-150201. This method includes a vacuum deposition method, an ion sputtering method, an ion plating method, an ion deposition method (IVD), a plasma deposition method (CVD), and the like. In this method, atomic or molecular vapor is produced by heating and evaporating by a method such as induction heating, and the vapor is attached to the surface of the sintered alloy. In the ion sputtering method, an inert gas such as Ar is introduced into a vacuum vessel, ionized by a discharge, accelerated by an electric field, and bombarded a raw material target to form raw material ions, which are then bonded together. This is a method of attaching to the surface of gold. In the ion plating method, a raw material is heated and evaporated by a method such as resistance heating, electron beam heating, or RF induction heating to form a vapor, which is then collided with thermoelectrons to form an ion stream of molecules or atoms of the raw material. This is a method of accelerating and depositing a film on the surface of the magnet. The ion vapor deposition method is a method in which a raw material vaporized by an electron gun, arc discharge or the like and ions from a raw material ion source are simultaneously and at a certain ratio adhered to a magnet surface. The plasma deposition method introduces a weight loss gas into the vacuum chamber,
In this method, the gas is turned into plasma by electric discharge or the like to form a film on the magnet surface.

本発明で使用出来る第１層用金属又は金属化合物に
は、Al、Ni、Cr、Cu、Co等の金属、シリカ、アルミナ、
クロミア、炭化チタン、窒化チタン、窒化アルミニウウ
ム、等の金属化合物がある。上記金属化合物は直接金属
化合物を蒸発させる方法と金属を蒸発させ、窒素、メタ
ン、酸素等のガスを導入し反応させる方法がある。Metals or metal compounds for the first layer that can be used in the present invention include metals such as Al, Ni, Cr, Cu, Co, silica, alumina,
There are metal compounds such as chromia, titanium carbide, titanium nitride, and aluminum nitride. The metal compound includes a method of directly evaporating the metal compound and a method of evaporating the metal and introducing and reacting a gas such as nitrogen, methane, or oxygen.

保護膜第２層 保護膜の第１層の表面には保護膜の第２層が形成され
る。第２層はｐ−キシリレン重合膜及び塩素化ｐ−キシ
リレン重合膜である。このような被覆には例えば米国ユ
ニオン・カーバイド社よりパリレンＮ（ポリｐ−キシリ
レン）、パリレンＣ（ポリモノクロクロロｐ−キシリレ
ン）、パリレンＤ（ポリジクロロｐ−キシリレン）等が
あるがガス透過性が低いので特にパリレンＣが好まし
い。ポリｐ−キシリレン等の膜は２量体のガスを減圧下
に熱分解することにより得られる。膜厚としては0.5μ
ｍ以上、好ましくは１〜20μｍである。Second layer of protective film A second layer of protective film is formed on the surface of the first layer of protective film. The second layer is a p-xylylene polymer film and a chlorinated p-xylylene polymer film. Such coatings include, for example, Parylene N (poly p-xylylene), Parylene C (polymonochlorochloro p-xylylene), Parylene D (polydichloro p-xylylene), etc. from Union Carbide, USA, but have gas permeability. Parylene C is particularly preferred because it is low. A film of poly-p-xylylene or the like can be obtained by thermally decomposing a dimer gas under reduced pressure. 0.5μ for film thickness
m, preferably 1 to 20 μm.

なお、必要ならばｐ−キシリレン重合膜及び塩素化ｐ
−キシリレン重合膜の被覆を有する高耐食性磁石をエポ
キシ樹脂その他の接着剤により電気又は電子装置の一部
に固定使用とするとこの重合膜の接触角が90度と高く撥
水性のため接着剤とのなじみが悪く充分な接着力が得ら
れず実用化の障害となる。従って他の部分への接着が必
要な場合には、重合膜の表面をプラズマ処理にかけるか
（特願平１−67521号）又は（或は更に）プラズマ重合
膜で被覆するか（特願昭63−109063号）により、ｐ−キ
シリレン重合膜又は塩素化ｐ−キシリレン重合膜と合成
樹脂接着剤との結合力を向上し得ることができる。If necessary, a p-xylylene polymer film and chlorinated p
-If a highly corrosion-resistant magnet having a coating of a xylylene polymer film is fixed to an electric or electronic device using an epoxy resin or other adhesive, the contact angle of the polymer film is as high as 90 degrees and the water repellency causes the adhesive to adhere to the adhesive. It does not fit well and does not provide sufficient adhesive strength, which hinders practical application. Therefore, when adhesion to other parts is necessary, the surface of the polymer film is subjected to plasma treatment (Japanese Patent Application No. 1-67521) or (or further) coated with a plasma polymer film (Japanese Patent Application No. No. 63-109063), it is possible to improve the bonding strength between the p-xylylene polymer film or the chlorinated p-xylylene polymer film and the synthetic resin adhesive.

プラズマ処理はAr、He、Ne等の希ガスH2、N2、O2、C
O、CO2、H2O、NOX、NO2、NH3のガス等を真空室に導入
し、プラズマ化しこれを重合膜に接触させることにより
行なわれる。プラズマ処理の条件としては通常次ぎのも
のを使用する。ガス圧力0.01〜10Torrにて電源は直流、
交流が使用でき、交流の周波数は50Hzから5GHzまで使用
できる。サンプルの形状及び量により処理条件は異なる
が使用電力10W〜10KW処理時間0.5秒〜10分に設定するこ
とができる。処理後の表面の接触角は30゜以下が望まし
いプラズマ処理はｐ−キシリレン重合膜及び塩素化ｐ−
キシリレン重合膜の表面を活性化し、使用するガスの種
類により各種の活性なラジカル、OH基等の官能基が生じ
その後に形成されるプラズマ重合膜又は合成樹脂膜に対
する反応性、濡れ性が改善され、接着剤が基体に充分入
り込む結果（アンカー効果）接着性を大幅に改善し、更
に表面硬度を大幅に向上させる。Plasma treatment is performed on rare gases such as Ar, He, Ne, etc., H 2 , N 2 , O 2 , C
This is performed by introducing a gas such as O, CO 2 , H 2 O, NO X , NO 2 , and NH 3 into a vacuum chamber, generating plasma, and bringing the plasma into contact with the polymer film. The following conditions are usually used for the plasma treatment. When the gas pressure is 0.01 to 10 Torr, the power supply is DC,
AC can be used, and the frequency of AC can be used from 50Hz to 5GHz. Although the processing conditions vary depending on the shape and amount of the sample, the power consumption can be set to 10 W to 10 KW and the processing time can be set to 0.5 seconds to 10 minutes. The contact angle of the surface after the treatment is preferably 30 ° or less. The plasma treatment is a p-xylylene polymer film and a chlorinated p-
The surface of the xylylene polymer film is activated, and various active radicals and functional groups such as OH groups are generated depending on the type of gas used.The reactivity and wettability of the subsequently formed plasma polymerized film or synthetic resin film are improved. As a result, the adhesive sufficiently penetrates into the substrate (anchor effect), thereby greatly improving the adhesiveness and further significantly improving the surface hardness.

プラズマ重合膜は、従来知られている任意のモノマー
ガスを使用し得る。例えばメタン、エタノール、プロパ
ン、ブタン、ペンタン、エチレン、プロピエン、ブテ
ン、ブタジエン、アセチレン、メチルアセチレン等の炭
化水素モノマーの他、テトラメトキシシラン等のケイ素
系モノマー、テトラフルオロエチレン等のフッ化水素系
モノマー、メチルメタアクリレート等を挙げることがで
きる。特に実質的に炭素と水素のみからなるプラズマ重
合膜は被膜を形成したもので、表面にち密でピンホール
の無い硬質の膜を形成し、耐食性が良好で、長期安定性
にすぐれた磁気特性を保つことができるという利点を有
するので好ましく、中でも原子数の比（原子組成比）で
表わして好ましくはH/C＝1.5以下であると三次元的に充
分架橋した特性の良いプラズマ重合膜が形成できる。こ
の場合、膜厚が0.2μｍ以下で充分な耐食性が得られ
る。このようなプラズマ重合保護膜は炭化水素モノマー
ガスの量を少なくし、反応圧力を低くし、且つ印加電力
を大きくすることにより生成し得る。すなわち、反応圧
力を低く印加電力を大きくすることにより、モノマー単
位量あたりの分解エネルギーが大きく成って分解が進
み、架橋したプラズマ重合保護膜が形成できる。本発明
の実施例に適当なエネルギー密度Ｗは108J/kg以上であ
る。その他キャリアガスとして水素、不活性ガス等のガ
スが使用できる。ただし不可避不純物として入ってくる
微量以上の酸素は用いてはならない。このように不可避
的な不純物ガスを除いて実質的に炭素と水素のみから成
る時高い耐食性と良好な接着性を示すことになる。更
に、プラズマ重合膜を形成するとき、磁石の温度を上げ
ておくことにより更に効果を上げることができる。For the plasma polymerized film, any conventionally known monomer gas can be used. For example, in addition to hydrocarbon monomers such as methane, ethanol, propane, butane, pentane, ethylene, propylene, butene, butadiene, acetylene, and methylacetylene, silicon monomers such as tetramethoxysilane, and hydrogen fluoride monomers such as tetrafluoroethylene And methyl methacrylate. In particular, a plasma polymerized film consisting essentially of only carbon and hydrogen is a coated film that forms a hard film with no pinholes on the surface and has good corrosion resistance and excellent magnetic properties with excellent long-term stability. It is preferable because it has the advantage that it can be maintained. Above all, if it is expressed by the ratio of the number of atoms (atomic composition ratio), preferably when H / C is 1.5 or less, a plasma polymerized film having good properties that is sufficiently cross-linked three-dimensionally is formed. it can. In this case, when the film thickness is 0.2 μm or less, sufficient corrosion resistance can be obtained. Such a plasma polymerization protective film can be formed by reducing the amount of hydrocarbon monomer gas, lowering the reaction pressure, and increasing the applied power. That is, by lowering the reaction pressure and increasing the applied electric power, the decomposition energy per unit amount of the monomer increases, and the decomposition proceeds, whereby a crosslinked plasma polymerization protective film can be formed. The energy density W suitable for the embodiment of the present invention is 10 8 J / kg or more. In addition, a gas such as hydrogen or an inert gas can be used as the carrier gas. However, a small amount of oxygen that enters as unavoidable impurities must not be used. As described above, when substantially composed of only carbon and hydrogen except for the inevitable impurity gas, high corrosion resistance and good adhesion are exhibited. Further, when the plasma polymerization film is formed, the effect can be further improved by increasing the temperature of the magnet.

なお、必要であればこのｐ−キシリレン重合膜又は塩
素化ｐ−キシリレン重合膜を有する高耐食性磁石の上に
施される合成樹脂はエポキシ樹脂、アクリル樹脂、およ
びメラミン樹脂等が施される（特願平１−103344号）。If necessary, an epoxy resin, an acrylic resin, a melamine resin, or the like is applied to the synthetic resin applied on the high corrosion-resistant magnet having the p-xylylene polymer film or the chlorinated p-xylylene polymer film. No. 1-103344).

（実施例の説明） 磁石の製造 原料粉末を合金の組成がNd15Fe77B8となる様に秤量
し、高周波溶解し、冷却して、鋳塊を製造した。次ぎの
これをスタンプミルにより粗粉砕し、更にボールミルで
微粉砕した。The raw material powder (Example of description) magnet was weighed as the composition of the alloy is Nd 15 Fe 77 B 8, high-frequency heating, and cooled, to produce an ingot. Next, this was roughly pulverized by a stamp mill and further finely pulverized by a ball mill.

この粉末を金型で直方体形に圧縮成形した。得られた
成形体を1100℃、１時間、Ar雰囲気中で焼結した。表面
粗度を測定したところJISの表面粗さRa2.1であった。真
空度５×10-5Torr以下にした後、Arガスを導入し圧力を
１×10-2Torrにし、500Vで15分間放電して表面の酸化物
等の汚れを除去した。以下の実施例ではこの焼結合金を
使用した。This powder was compression-molded into a rectangular parallelepiped shape by a mold. The obtained molded body was sintered at 1100 ° C. for 1 hour in an Ar atmosphere. The surface roughness measured was JIS surface roughness Ra 2.1. After reducing the degree of vacuum to 5 × 10 −5 Torr or less, Ar gas was introduced to adjust the pressure to 1 × 10 −2 Torr, and discharge was performed at 500 V for 15 minutes to remove stains such as oxides on the surface. This sintered alloy was used in the following examples.

実施例１ 上記の清浄化した焼結合金の表面に直ちにイオンプレ
ーテイング法によりA1の薄膜を厚さ約５μｍに付着した
（比較例１）。次いでパリレンＣを厚さ５μｍになるま
で気相重合した。特性を測定したところ表１の結果を得
た。Example 1 A thin film of A1 was immediately adhered to the surface of the cleaned sintered alloy to a thickness of about 5 μm by an ion plating method (Comparative Example 1). Then, Parylene C was vapor-phase polymerized to a thickness of 5 μm. When the characteristics were measured, the results shown in Table 1 were obtained.

なお、耐食性、磁性低下及び寸法安定性を次ぎの基準
で評価した。In addition, corrosion resistance, magnetic reduction, and dimensional stability were evaluated according to the following criteria.

耐食性・・・35℃の５％食塩水をサンプルに噴霧し、錆
が発生するまでの時間を測定した。Corrosion resistance: A 5% saline solution at 35 ° C was sprayed on the sample, and the time until rust was generated was measured.

寸法安定性・・・サンプルの寸法の測定を20箇所で行な
い、そのばらつきを示す。Dimensional stability: The dimensions of the sample are measured at 20 locations, and the variation is shown.

磁性低下・・・90℃、90％の高温高湿下に90日間保った
後の磁性低下率を示す。Decrease in magnetism: The rate of decrease in magnetism after 90 days at 90 ° C. and 90% high temperature and high humidity.

実施例２ イオン化蒸着法により上記焼結合金の表面にCuの薄膜
をを厚さ約５μｍに付着した（比較例２）。次いでパリ
レンＣを厚さ10μｍになるまで気相重合した。Example 2 A Cu thin film having a thickness of about 5 μm was attached to the surface of the sintered alloy by ionization vapor deposition (Comparative Example 2). Subsequently, Parylene C was subjected to gas phase polymerization until the thickness became 10 μm.

比較例１、２ 比較例１、２は実施例１、２においてそれぞれパリレ
ンＣの膜を形成しないものである。Comparative Examples 1 and 2 Comparative Examples 1 and 2 are different from Examples 1 and 2, respectively, in that no parylene C film is formed.

比較例３ 比較例１の処理の後にショットピーニングによる封孔
処理を施し、次ぎにクロメート処理を施した。Comparative Example 3 After the treatment of Comparative Example 1, a sealing treatment by shot peening was performed, and then a chromate treatment was performed.

比較例４ 比較例２の処理の後にエポキシ樹脂を塗布し加熱硬化
した。Comparative Example 4 After the treatment of Comparative Example 2, an epoxy resin was applied and cured by heating.

更に、実施例１及び比較例４の切片を作り、断面を観
察したところ、実施例１のものには気泡が全くなく細孔
の中は完全に充填されていた。比較例４のものは細孔の
上に薄層が形成されてはいたが樹脂と磁石が密着してい
ない部分が点在していた。 Further, sections of Example 1 and Comparative Example 4 were prepared and their cross sections were observed. As a result, it was found that there was no air bubble in Example 1 and the pores were completely filled. In the case of Comparative Example 4, a thin layer was formed on the fine pores, but portions where the resin and the magnet did not adhere closely were scattered.

（作用効果） 実施例及び比較例から、本発明のｐ−パラキシリレン
等の気相重合膜は蒸着膜を介在するとき、耐食性、及び
寸法安定性が極めて優れたものとなることが分かる。こ
れに対し蒸着金属のみでは耐食性が悪い。封孔処理をし
た場合でも耐食性は充分でない。一方樹脂被覆を有する
ときは恐らく内部水分が原因となる磁性の低下が見ら
れ、又寸法精度に問題があった。(Effects) From the examples and the comparative examples, it can be seen that the vapor-phase polymerized film such as p-paraxylylene of the present invention has extremely excellent corrosion resistance and dimensional stability when a deposited film is interposed. On the other hand, the corrosion resistance is poor only with the deposited metal. Even when the sealing treatment is performed, the corrosion resistance is not sufficient. On the other hand, when it has a resin coating, a decrease in magnetism possibly caused by internal moisture was observed, and there was a problem in dimensional accuracy.

───────────────────────────────────────────────────── フロントページの続き (72)発明者 上田 国博 東京都中央区日本橋１丁目13番１号 テ ィーディーケイ株式会社内 (72)発明者 柴原 正典 東京都中央区日本橋１丁目13番１号 テ ィーディーケイ株式会社内 (56)参考文献 特開 昭64−34156（ＪＰ，Ａ) 特開 昭55−103714（ＪＰ，Ａ) ────────────────────────────────────────────────── ─── Continuing on the front page (72) Kunihiro Ueda 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDK Corporation (72) Inventor Masanori Shibahara 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDK (56) References JP-A-64-34156 (JP, A) JP-A-55-103714 (JP, A)

Claims (4)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】多孔質表面を有する稀土類元素（Ｙを含
む）−硼素−鉄系合金焼結体の表面に気相めっき層と、
それに続く気相重合ｐ−キシリレン重合膜又は塩素化ｐ
−キシリレン重合膜の保護被覆を形成したことを特徴と
する耐食性永久磁石。A vapor-phase plating layer on the surface of a rare earth element (including Y) -boron-iron alloy sintered body having a porous surface;
Subsequent gas-phase polymerized p-xylylene polymer film or chlorinated p
-A corrosion-resistant permanent magnet having a protective coating of a xylylene polymer film. 【請求項２】合金は稀土類元素８〜30原子％、硼素２〜
28原子％、及び鉄42〜90原子％を主成分とする前記第１
項記載の耐食性永久磁石。2. The alloy comprises 8 to 30 atomic% of rare earth element and 2 to 2 boron atom.
28. The above-mentioned first, which is mainly composed of 28 atomic% and 42 to 90 atomic% of iron.
Corrosion-resistant permanent magnet according to the item. 【請求項３】多孔質表面を有する稀土類元素−ホウ素−
鉄系合金焼結体の表面に金属上記を接触させてめっき相
を形成し、次いでｐ−キシリレン二量体又は塩素化ｐ−
キシリレン二量体を熱分解してｐ−キシリレン又は塩素
化ｐ−キシリレンのラジカルを形成し、このラジカルを
前記めっき層の表面で重合させて保護被覆を形成するこ
とを特徴とする耐食性永久磁石の製造方法。3. A rare earth element having a porous surface-boron-
The plating phase is formed by bringing the above metal into contact with the surface of the iron-based alloy sintered body, and then p-xylylene dimer or chlorinated p-
A corrosion-resistant permanent magnet, wherein a xylylene dimer is thermally decomposed to form radicals of p-xylylene or chlorinated p-xylylene, and the radicals are polymerized on the surface of the plating layer to form a protective coating. Production method. 【請求項４】合金は稀土類元素８〜30原子％、硼素２〜
28原子％、及び鉄42〜90原子％を主成分とする前記第３
項記載の耐食性永久磁石の製造方法。4. The alloy comprises 8 to 30 atomic% of rare earth element and 2 to 2 boron atom.
28. The above-mentioned third, which is mainly composed of 28 atomic% and 42 to 90 atomic% of iron.
The method for producing a corrosion-resistant permanent magnet according to the above item.
JP1175645A 1989-03-22 1989-07-10 Rare earth iron-based alloy sintered magnet having p-xylylene polymer film and its manufacturing method Expired - Fee Related JP2753588B2 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP1175645A JP2753588B2 (en) 1989-07-10 1989-07-10 Rare earth iron-based alloy sintered magnet having p-xylylene polymer film and its manufacturing method
US07/497,549 US5154978A (en) 1989-03-22 1990-03-22 Highly corrosion-resistant rare-earth-iron magnets

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1175645A JP2753588B2 (en) 1989-07-10 1989-07-10 Rare earth iron-based alloy sintered magnet having p-xylylene polymer film and its manufacturing method

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JP2753588B2 true JP2753588B2 (en) 1998-05-20

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Publication number Priority date Publication date Assignee Title
EP3319098A1 (en) 2016-11-02 2018-05-09 Abiomed Europe GmbH Intravascular blood pump comprising corrosion resistant permanent magnet
EP3425204B1 (en) * 2017-07-04 2021-04-14 Levitronix GmbH Magnetic rotor and machine with such a rotor
ES2842882T3 (en) * 2018-05-08 2021-07-15 Abiomed Europe Gmbh Corrosion resistant permanent magnet and intravascular blood pump comprising magnet
EP3822996A1 (en) * 2019-11-12 2021-05-19 Abiomed Europe GmbH Corrosion-resistant permanent magnet for an intravascular blood pump

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JPS55103714A (en) * 1979-02-01 1980-08-08 Takagi Kogyo Kk Total periphery coating for permanent magnet
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